Why Yahoo Maps are so poor?

Both Yahoo! and Google allow you to embed rich and interactive maps into your website (let's assume you have one), which is especially relevant and useful in e-tourism sites. However, in the battle between these two giants, it seems that Yahoo! is the biggest looser. A quick examination of the two services demonstrates how mediocre the coverage provided by Yahoo! is in comparison to Google's. In terms of user experience, Yahoo! fails big time.

For example: let's pick a tiny and irrelevant city in Australia called Sydney (only 4.2 million people). While Google provides you with a detailed map, Yahoo! presents only the general shape of the city in white. No streets, no roads - it's the Aussie outback after all. Aren't convinced yet? type Johannesburg, another insignificant city, and see what you get. Once again - the big white. When you try to zoom in to search for streets, Yahoo! kindly asks you to zoom out, because the data is unavailable.

Here is an amazing tool I found, that shows you how the two systems work side by side: http://www.sergeychernyshev.com/maps.html

I guess the good people at Yahoo! work very hard to improve their services, so the coverage will probably get better in the future. Meanwhile, if you're considering maps for your site - go with Google. It's a safer bet.